Control method and control device for charging time sharing

ABSTRACT

A control method for charging time sharing in a display apparatus, which includes receiving image data including a plurality of pixel data signals corresponding to a plurality of display driving periods, each display driving period associated with pixel data signals of a respective row of the display apparatus, calculating a plurality of gray variations corresponding to the plurality of display driving periods according to the plurality of pixel data signals, adjusting the plurality of display driving periods to generate a plurality of adjusted display driving periods according to the plurality of gray variations, and generating a gate clock signal according to the plurality of adjusted display driving periods.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a control method and control device,and more particularly, to a control method and control device capable ofrealizing charging time sharing.

2. Description of the Prior Art

With rapid development of display technology, traditional cathode raytube (CRT) displays have been gradually replaced by liquid crystaldisplays (LCDs). A LCD device utilizes a source driver and a gate driverto drive pixels on a display panel to display images. LCD devices nowhave higher resolutions, and as a result data throughput between thetiming controller and the source drivers has greatly increased.

In general, a respective gate driving signal is in an enable state sothat a respective pixel row of a display panel is turned on andcapacitors of corresponding pixels are charged to gray voltage levels bythe source driver for displaying respective image data during therespective display driving period. Fixed display driving periods areusually applied for displaying the image data. For example, please referto FIG. 1 , the duration of each of the display driving periods T1-TN is1H. However, the higher the gray level of the pixel image data is, thelonger the charging time takes. The gray levels of the image data may bevaried at different display driving periods. Since the duration of eachdisplay driving period is fixed, some pixels on the respective row maybe charged insufficiently and unable to desire gray voltage levels, thuscausing the LCD device to exhibit color inequality due to charginginequality. Thus, there is a need for improvement.

SUMMARY OF THE INVENTION

It is therefore an objective of the present invention to provide acontrol method and a control device capable of realizing charging timesharing purpose.

The present invention discloses a control method for charging timesharing in a display apparatus, comprising: receiving image dataincluding a plurality of pixel data signals corresponding to a pluralityof display driving periods, each display driving period associated withpixel data signals of a respective row of the display apparatus;calculating a plurality of gray variations corresponding to theplurality of display driving periods according to the plurality of pixeldata signals; adjusting the plurality of display driving periods togenerate a plurality of adjusted display driving periods according tothe plurality of gray variations; and generating a gate clock signalaccording to the plurality of adjusted display driving periods.

The present invention further discloses a control device for chargingtime sharing, comprising: a memory unit for receiving and storing imagedata, the image data including a plurality of pixel data signalscorresponding to a plurality of display driving periods, each displaydriving period associated with pixel data signals of a respective row ofa display apparatus; a calculation unit for calculating a plurality ofgray variations corresponding to the plurality of display drivingperiods according to the plurality of pixel data signals; an adjustmentunit for adjusting the plurality of display driving periods to generatea plurality of adjusted display driving periods according to theplurality of gray variations; and a control signal generation unit forgenerating a gate clock signal according to the plurality of adjusteddisplay driving periods.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a signal timing diagram of an LCD driving device according tothe prior art.

FIG. 2 is a schematic diagram of a display apparatus according to anembodiment of the invention.

FIGS. 3-4 are signal timing diagrams of alternative embodiments of thedisplay apparatus shown in FIG. 2 .

FIG. 5 is a flow diagram of a procedure according to an exemplaryembodiment of the present invention.

DETAILED DESCRIPTION

Certain terms are used throughout the description and following claimsto refer to particular components. As one skilled in the art willappreciate, electronic equipment manufacturers may refer to a componentby different names. This document does not intend to distinguish betweencomponents that differ in name but not function. In the followingdescription and the claims as well, the terms “include” and “comprise”are used in an open-ended fashion, and thus should be interpreted tomean “include, but not limited to . . . ”.

Please refer to FIG. 2 , which is a schematic diagram of a displayapparatus 20 according to an embodiment of the invention. The displayapparatus 20 includes a control device 202, a gate driver 204, a sourcedriver 206, a display panel 208, data lines D1-DM and gate lines G1-GN.The display panel 208 includes M by N pixels P arranged in a matrixpattern. The data lines D1-DM and the gate lines G1-GN are utilized forapplying signals to the pixels P. The gate driver 204 provides gatedriving signals G(1)-G(N) to the gate lines G1-GN to turn on respectivepixel rows. The source driver 206 provides data driving signalsD(1)-D(M) to the data lines D1-DM. For example, the data driving signalsD(1)-D(M) are provided to the pixels connected to the respectiveturned-on pixel row during a respective driving period.

The control device 202 includes a memory unit 210, a calculation unit212, an adjustment unit 214 and a control signal generation unit 216.The memory unit 210 is utilized for receiving and storing image data.The image data includes a plurality of pixel data signals correspondingto display driving periods T1-TN. Each display driving period associateswith pixel data signals of a respective row of the display panel 208.The calculation unit 212 is utilized for calculating a plurality of grayvariations corresponding to the display driving periods T1-TN accordingto the plurality of pixel data signals. The adjustment unit 214 isutilized for adjusting the display driving periods T1-TN to generateadjusted display driving periods T1′-TN′ according to the plurality ofgray variations. The control signal generation unit 216 is utilized forgenerating a gate clock signal CPV according to the adjusted displaydriving periods T1′-TN′.

For calculating each gray variation corresponding to a respectivedisplay driving period, the calculation unit 212 may calculatevariations of gray level of pixel data signals associated with therespective display driving period and the pixel data signals associatedwith a previous display driving period prior to the respective displaydriving period. In an embodiment, the calculation unit 212 calculates amaximum change of gray voltage levels between the respective pixel datasignals corresponding to the respective display driving period and therespective pixel data signals corresponding to a previous displaydriving period prior to the respective display driving period, to obtaina respective gray variation corresponding to the respective displaydriving period.

For example, the plurality of gray variations corresponding to thedisplay driving periods T1-TN may be calculated by the calculation unit212 according to the following equations:Vs(Tn)=Max{Δ[Xm(Tn−1)→Xm(Tn)],m=1, . . . ,M},n=1, . . . ,N  (1)

In equation (1), Vs(Tn) represents n-th gray variation corresponding ton-th display driving period, Tn represents n-th display driving period,Tn−1 represents a previous display driving period prior to the n-thdisplay driving period, Xm(Tn−1) represents a respective gray voltagelevel of a respective pixel data signal of m-th column of the displaypanel 208 corresponding to a previous display driving period prior tothe n-th display driving period, Xm(Tn) represents a respective grayvoltage level of a respective pixel data signal of m-th column of thedisplay panel 208 corresponding to the n-th display driving period. Inequation (1), Δ(⋅) is a delta function indicating the difference betweenrespective gray voltage levels, and Δ[Xm (Tn−1)→Xm(Tn)] represents theamount of change between the respective gray voltage levels of therespective pixel data signals of m-th column of the display panel 208corresponding to the n-th display driving period and the previousdisplay driving period prior to the n-th display driving period. In anembodiment. Δ[Xm(Tn−1)→Xm(Tn)] may be obtained by calculating anabsolute difference of the respective gray voltage level of a respectivepixel data signal of m-th column of the display panel 208 correspondingto a previous display driving period prior to the n-th display drivingperiod and the respective gray voltage level of a respective pixel datasignal of m-th column of the display panel 208 corresponding to the n-thdisplay driving period. In an embodiment, Δ[Xm(Tn−1)→Xm(Tn)] may beobtained by calculating a difference value of the respective grayvoltage level of a respective pixel data signal of m-th column of thedisplay panel 208 corresponding to a previous display driving periodprior to the n-th display driving period and the respective gray voltagelevel of a respective pixel data signal of m-th column of the displaypanel 208 corresponding to the n-th display driving period.

Max(⋅) is a function indicating taking a maximum of the value in thefollowing parentheses. Max{Δ[Xm(Tn−1)→Xm(Tn)]} represents a maximumvalue of gray voltage level change corresponding to the n-th displaydriving period and a previous display driving period prior to the n-thdisplay driving period among M columns of the display panel 208.

Moreover, the adjustment unit 214 adjusts the display driving periodsT1-TN to generate the adjusted display driving periods T1′-TN′ accordingto the calculated gray variations. That is, the display driving periodsT1-TN can be reallocated to the adjusted display driving periods T1′-TN′according to the gray variations. In an embodiment, the adjustment unit214 may adjust the plurality of display driving periods T1-TN togenerate the plurality of adjusted display driving periods T1′-TN′according to a ratio of the plurality of gray variations. In anembodiment, for two adjacent display driving periods, the calculationunit 212 calculates a first gray variation corresponding to a firstdisplay driving period according to the pixel data signals associatedwith the first display driving period and the pixel data signalsassociated with a display driving period prior to the first displaydriving period. The calculation unit 212 calculates a second grayvariation corresponding to a second display driving period according tothe pixel data signals associated with the second display driving periodand the pixel data signals associated with the first display drivingperiod prior to the second display driving period. As such, theadjustment unit 214 compares the first gray variation with the secondgray variation. When the first gray variation is greater than the secondgray variation, the adjustment unit 214 adjusts the first displaydriving period to generate an adjusted first display driving period andadjusts the second display driving period to generate an adjusted seconddisplay driving period. For example, the adjustment unit 214 increasesthe first display driving period to generate an adjusted first displaydriving period and decreases the second display driving period togenerate an adjusted second display driving period. Therefore, the firstdisplay driving period is shorter than the adjusted first displaydriving period and the second display driving period is longer than theadjusted second display driving period after adjustment. For example, aratio of the adjusted first display driving period and adjusted seconddisplay driving period is substantially equal to a ratio of the firstgray variation and the second gray variation. Since the adjusted firstdisplay driving period is longer than the first display driving period,the pixel data signals associated with the first display driving periodhas longer charging time for realizing respective pixel gray level.

In addition, when the first gray variation is smaller than or equal tothe second gray variation, the adjustment unit 214 may maintains thefirst display driving period and provides the first display drivingperiod as an adjusted first display driving period. Similarly, theadjustment unit 214 maintains the second display driving period andprovides the second display driving period as an adjusted second displaydriving period.

The control signal generation unit 216 generates a gate clock signal CPVaccording to the adjusted display driving periods T1′-TN′ and providesthe gate clock signal CPV to the gate driver 204. Each period of thegate clock signal CPV corresponds to a respective adjusted displaydriving period of the adjusted display driving periods T1′-TN′. Forexample, each period of the gate clock signal CPV has the same length asthe respective adjusted display driving period. The control signalgeneration unit 216 generates a start signal STV according to the gateclock signal CPV. The start signal STV is utilized for indicating whento start outputting the gate driving signals G(1)-G(N). The controlsignal generation unit 216 generates an output enable signal OEcorresponding to the adjusted display driving periods T1′-TN′ accordingto the gate clock signal CPV. The output enable signal OE is utilizedfor indicating when to output the gate driving signals G(1)-G(N) and thedurations of the gate driving signals G(1)-G(N). Each period of theoutput enable signal OE the gate clock signal CPV corresponds to arespective period of the gate clock signal CPV. Therefore, the gatedriver 204 generates the gate driving signals G(1)-G(N) according to atleast one of the gate clock signal CPV, the start signal STV and theoutput enable signal OE. Each period of the gate driving signalcorresponds to one respective adjusted display driving period.

The control signal generation unit 216 generates a latch data signal LDcorresponding to the adjusted display driving periods T1′-TN′ accordingto the gate clock signal CPV and provides the latch data signal LD tothe source driver 206. Each period of the latch data signal LDcorresponds to a respective adjusted display driving period of theadjusted display driving periods T1′-TN′. For example, each falling edgeof the latch data signal LD corresponds to a respective adjusted displaydriving period. The latch data signal LD is utilized for indicating datareception and data output for the source driver 206. The source driver206 generates the data driving signals D(1)-D(M) according to latch datasignal LD.

In other words, since the adjusted display driving periods T1′-TN′ aregenerated according to the gray variations of corresponding pixel datasignals and the gate driving signals G(1)-G(N) and the data drivingsignals D(1)-D(M) are generated based on the adjusted display drivingperiods T1′-TN′, the pixel data signals requiring longer charging timecan be displays in a longer display driving period, so as to providesufficient charging time for display.

Please refer to FIG. 3 , which is a signal timing diagram of the displayapparatus 20 shown in FIG. 2 . Sequentially from the top of FIG. 3 , thesignal waveforms are: the gate clock signal CPV, the start signal STV,the latch data signal LD, the gray variations Vs, the output enablesignal OE and the gate driving signals G(1)-G(N). Taking charging timesharing of two adjacent display driving periods T3 and T4 for example,suppose the duration of each of the display driving periods T1-TN is 1IIbefore adjustment. For example, a gray variation Vs(T3) corresponding tothe display driving period T3 and a gray variation Vs(T4) correspondingto the display driving period T4 can be calculated by the calculationunit 212 according to the following equations:Vs(T3)=Max{Δ[Xm(T2)→Xm(T3)],m=1, . . . ,M}  (2)Vs(T4)=Max{Δ[Xm(T3)→Xm(T4)],m=1, . . . ,M}  (3)

When the gray variation Vs(T3) is greater than the gray variationVs(T4), the adjustment unit 214 increases the display driving period T3to generate an adjusted display driving period T3′ and decreases thedisplay driving period T4 to generate an adjusted display driving periodT4′. As shown in FIG. 3 , the display driving period T3 is shorter thanthe adjusted display driving period T3′. The display driving period T4is longer than the adjusted display driving period T4′. The totalduration (i.e. 2H) of the display driving period T3 and the displaydriving period T4 is equal to the total duration (i.e. 2H) of theadjusted display driving period T3′ and the adjusted display drivingperiod T4′. As shown in FIG. 3 , the charging orders are gate linesG1→G2→G3→G4→ . . . . The gate driving signal G(1) is outputted duringthe adjusted display driving period T1′ to turn on the pixels of thefirst row of the display panel 208. Pixel data signals of the first rowof the image data are displayed on the first row of the display panel208 during the adjusted display driving period T1′. The gate drivingsignal G(2) is outputted during the adjusted display driving period T2′to turn on the pixels of the second row of the display panel 208. Pixeldata signals of the second row of the image data are displayed on thesecond row of the display panel 208 during the adjusted display drivingperiod T2′. Such like this, the gate driving signals G(3) and G(4) aresequentially outputted during the adjusted display driving periods T3′and T4′ to turn on the pixels of the third row and the fourth row of thedisplay panel 208. Pixel data signals of the third row and the fourthrow of the image data are displayed on the third row and the fourth rowof the display panel 208 during the adjusted display driving periods T3′and T4′.

In addition, please further refer to FIG. 3 , each falling edge of thelatch data signal LD corresponds to the end of a respective adjusteddisplay driving period. The interval of time between each two adjacentrising edges of the latch data signal LD is 1H, so that data receptiontiming of the source driver 206 may maintain the same state withoutchange.

Please refer to FIG. 4 , which is a signal timing diagram of analternative embodiment of the display apparatus 20 shown in FIG. 2 .Different from FIG. 3 , the charging orders are gate lines G1→G3→G2→G4→. . . . Sequentially from the top of FIG. 4 , the signal waveforms are:the gate clock signal CPV, the start signal STV, the latch data signalLD, the gray variations Vs, the output enable signal OE and the gatedriving signals G(1)-G(N). Taking charging time sharing of two adjacentdisplay driving periods T3 and T4 for example, suppose the duration ofeach of the display driving periods T1-TN is 1H before adjustment.Similarly, a gray variation Vs(T3) corresponding to the display drivingperiod T3 and a gray variation Vs(T4) corresponding to the displaydriving period T4 can be calculated by the calculation unit 212according to the above equations (2) and equations (3). When the grayvariation Vs(T3) is greater than the gray variation Vs(T4), theadjustment unit 214 increases the display driving period T3 to generatean adjusted display driving period T3′ and decreases the display drivingperiod T4 to generate an adjusted display driving period T4′. As shownin FIG. 4 , the display driving period T3 is shorter than the adjusteddisplay driving period T3′. The display driving period T4 is longer thanthe adjusted display driving period T4′. Therefore, the gate drivingsignal G(1) is outputted during the adjusted display driving period T1′to turn on the pixels of the first row of the display panel 208. Pixeldata signals of the first row of the image data are displayed on thefirst row of the display panel 208 during the adjusted display drivingperiod T1′. The gate driving signal G(3) is outputted during theadjusted display driving period T2′ to turn on the pixels of the thirdrow of the display panel 208. Pixel data signals of the third row of theimage data are displayed on the third row of the display panel 208during the adjusted display driving period T2′. Such like this, the gatedriving signals G(2) and G(4) are sequentially outputted during theadjusted display driving periods T3′ and T4′ to turn on the pixels ofthe second row and the fourth row of the display panel 208. Pixel datasignals of the second row and the fourth row of the image data aredisplayed on the second row and the fourth row of the display panel 208during the adjusted display driving periods T3′ and T4′.

In an embodiment, taking the charging time sharing for every threeadjacent display driving periods for example, please refer to FIG. 5 .FIG. 5 is a flow diagram of a procedure 50 according to an exemplaryembodiment of the present invention. The procedure 50 in FIG. 5 can beapplied to the embodiments shown in FIG. 2 . The procedure 50 includesthe following steps:

Step 500: Start.

Step 502: Provide pixel data signal.

Step 504: Determine whether gray variation Vs(T1) is greater than grayvariation Vs(T2); if gray variation Vs(T1) is greater than grayvariation Vs(T2), go to Step 506, if gray variation Vs(T1) is smallerthan gray variation Vs(T2), go to

Step 516.

Step 506: Determine whether gray variation Vs(T2) is greater than grayvariation Vs(T3); if gray variation Vs(T2) is greater than grayvariation Vs(T3), go to Step 508, if gray variation Vs(T2) is smallerthan gray variation Vs(T3), go to Step 510.

Step 508: Generate the adjusted display driving periods T1′, T2′, T3′;T1′:T2′:T3′=Vs(T1):Vs(T2):Vs(T3).

Step 510: Determine whether gray variation Vs(T1) is greater than grayvariation Vs(T3); if gray variation Vs(T1) is greater than grayvariation Vs(T3), go to Step 512, if gray variation Vs(T1) is smallerthan gray variation Vs(T3), go to Step 514.

Step 512: Generate the adjusted display driving periods T1′, T2′, T3′;T1′:T2′=Vs(T1):Vs(T2), T3′=T3.

Step 514: Generate the adjusted display driving periods T1′, T2′, T3′;T1′:T2′=Vs(T1):Vs(T2), T3′=T3.

Step 516: Determine whether gray variation Vs(T2) is greater than grayvariation Vs(T3); if gray variation Vs(T2) is greater than grayvariation Vs(T3), go to Step 518, if gray variation Vs(T2) is smallerthan gray variation Vs(T3), go to Step 524.

Step 518: Determine whether gray variation Vs(T1) is greater than grayvariation Vs(T3); if gray variation Vs(T1) is greater than grayvariation Vs(T3), go to Step 520, if gray variation Vs(T1) is smallerthan gray variation Vs(T3), go to Step 522.

Step 520: Generate the adjusted display driving periods T1′, T2′, T3′;T2′:T3′=Vs(T2):Vs(T3), T1′=T1.

Step 522: Generate the adjusted display driving periods T1′, T2′, T3′;T2′:T3′=Vs(T2):Vs(T3), T1′=T1.

Step 524: Generate the adjusted display driving periods T1′, T2′,T3′;T1+=T1, T2′=T2, T3′=T3.

According to the procedure 50, in Step 502, pixel data signals of rowsof the display panel 208 corresponding to display driving periods T1-TNare provided. The calculation unit 212 calculates gray variationsVs(T1), Vs(T2) and Vs(T3) corresponding to display driving periods T1,T2, T3 according to the above-mentioned equation (1).

In Step 504, the adjustment unit 214 determines whether the grayvariation Vs(T1) is greater than the gray variation Vs(T2). If the grayvariation Vs(T1) is greater than the gray variation Vs(T2), theadjustment unit 214 further determines whether the gray variation Vs(T2)is greater than the gray variation Vs(T3) (Step 506). If the grayvariation Vs(T2) is greater than the gray variation Vs(T3) (i.e.Vs(T1)>Vs(T2)>Vs(T3)), this means the gray variations are progressivelydecreased with display driving period. Accordingly, the adjustment unit214 adjusts the display driving periods T1, T2, T3 according to the grayvariation Vs(T1), the gray variation Vs(T2) and the gray variationVs(T3). The display driving periods T1, T2, T3 may be adjusted to theadjusted display driving periods T1′, T2′, T3′ respectively. Forexample, a ratio of the adjusted display driving periods T1′, T2′, T3′is substantially equal to a ratio of the gray variation Vs(T1), the grayvariation Vs(T2) and the gray variation Vs(T3) (Step 508). In otherwords, since the display driving periods T1, T2, T3 are reallocated tothe adjusted display driving periods T1′, T2′, T3′, the pixel datasignals associated with the display driving periods T1, T2, T3 would bedisplayed with charging time corresponding to the adjusted displaydriving periods T1′, T2′, T3′.

In Steps 512 and 514, the adjustment unit 214 generates the adjusteddisplay driving periods T1′, T2′, T3′. The adjustment unit 214 mayadjust the display driving periods T1, T2 according to the grayvariation Vs(T1) and the gray variation Vs(T2), so as to generate theadjusted display driving periods T1′, T2′. For example, a ratio of thedisplay driving periods T1′, T2′ is substantially equal to a ratio ofthe gray variation Vs(T1) and the gray variation Vs(T2). For example,the adjustment unit 214 keeps the display driving period T3 and providesthe display driving period T3 as the adjusted display driving periodsT3′.

In Step 516, the adjustment unit 214 determines whether the variationVs(T2) is greater than the gray variation Vs(T3). If the gray variationVs(T2) is smaller than the gray variation Vs(T3) (i.e.Vs(T1)<Vs(T2)<Vs(T3)), this means the gray variations are progressivelyincreased with display driving period. In such a situation, theadjustment unit 214 keeps the display driving periods T1, T2, T3 andprovides the display driving periods T1, T2, T3 as the adjusted displaydriving periods T1′, T2′, T3′ respectively (Step 524).

In Steps 520 and 522, the adjustment unit 214 generates the adjusteddisplay driving periods T1′, T2′, T3′. The adjustment unit 214 adjuststhe display driving periods T2, T3 according to the gray variationVs(T2) and the gray variation Vs(T3), so as to generate the adjusteddisplay driving periods T2′, T3′. For example, a ratio of the displaydriving periods T2′, T3′ is substantially equal to a ratio of the grayvariation Vs(T2) and the gray variation Vs(T3). For example, theadjustment unit 214 keeps the display driving period T1 and provides thedisplay driving period T1 as the adjusted display driving periods T1′.

In summary, the invention can re-assign the display driving periods toprovide the adjusted display driving periods based on gray variations ofthe display driving periods for charging time sharing. Since the gatedriving signals and the data driving signals are generated based on theadjusted display driving periods, the pixel data signals requiringlonger charging time can be displays in a longer display driving period,so as to provide sufficient charging time for display and avoid charginginequality.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A control method for charging time sharing in a display apparatus, comprising: receiving image data including a plurality of pixel data signals corresponding to a plurality of display driving periods, each display driving period associated with pixel data signals of a respective row of the display apparatus; calculating a plurality of gray variations corresponding to the plurality of display driving periods according to the plurality of pixel data signals; adjusting the plurality of display driving periods to generate a plurality of adjusted display driving periods by comparing the plurality of gray variations; and generating a gate clock signal according to the plurality of adjusted display driving periods, wherein the plurality of adjusted display driving period comprises an adjusted first display driving period and an adjusted second display driving period, an adjusted third display driving period and an adjusted fourth display driving period occurring in order and having different durations, and a total duration of the adjusted first display driving period and the adjusted second display driving period is equal to a total duration of the adjusted third display driving period and the adjusted fourth display driving period.
 2. The control method of claim 1, wherein the step of calculating a plurality of gray variations corresponding to the plurality of display driving periods according to the plurality of pixel data signals comprises: for each gray variation corresponding to a respective display driving period, calculating a maximum change of gray voltage levels between the respective pixel data signals corresponding to the respective display driving period and the respective pixel data signals corresponding to a previous display driving period prior to the respective display driving period.
 3. The control method of claim 1, wherein plurality of gray variations corresponding to the plurality of display driving periods are calculated according to the following equation: Vs(Tn)=Max{Δ[Xm(Tn−1)→Xm(Tn)],m=1, . . . ,M},n=1, . . . ,N where Vs(Tn) represents n-th gray variation corresponding to n-th display driving period; Tn represents n-th display driving period; Tn−1 represents a previous display driving period prior to the n-th display driving period; Xm(Tn−1) represents a respective gray voltage level of a respective pixel data signal of m-th column of the display apparatus corresponding to the previous display driving period prior to the n-th display driving period; Xm(Tn) represents a respective gray voltage level of a respective pixel data signal of m-th column of the display apparatus corresponding to the n-th display driving period; Δ(⋅) represents a delta function indicating the difference between respective gray voltage levels; Max (⋅) represents a function indicating taking a maximum of the value in the following parentheses; and n, N, m and M are positive integers, n is between 1 and N, m is between 1 and M.
 4. The control method of claim 1, wherein the step of calculating the plurality of gray variations corresponding to the plurality of display driving periods according to the plurality of pixel data signals comprises: calculating a first gray variation of the plurality of gray variations corresponding to a first display driving period of the plurality of display driving periods according to pixel data signals corresponding to the first display driving period and pixel data signals corresponding to a previous display driving period prior to the first display driving period; and calculating a second gray variation of the plurality of gray variations corresponding to a second display driving period of the plurality of display driving periods according to pixel data signals corresponding to the second display driving period and pixel data signals corresponding to the first display driving period, wherein the second display driving period is after the first display driving period.
 5. The control method of claim 4, wherein the step of adjusting the plurality of display driving periods to generate the plurality of adjusted display driving periods by comparing the plurality of gray variations comprises: comparing the first gray variation with the second gray variation; and when the first gray variation is greater than the second gray variation, increasing the first display driving period to generate the adjusted first display driving period and decreasing the second display driving period to generate the adjusted second display driving period.
 6. The control method of claim 5, wherein the first display driving period is shorter than the adjusted first display driving period, the second display driving period is longer than the adjusted second display driving period, and the total duration of the first display driving period and the second display driving period is equal to the total duration of the adjusted first display driving period and the adjusted second display driving period.
 7. The control method of claim 1, wherein the step of adjusting the plurality of display driving periods to generate the plurality of adjusted display driving periods by comparing the plurality of gray variations comprises: adjusting the plurality of display driving periods to the plurality of adjusted display driving periods according to a ratio of the plurality of gray variations.
 8. The control method of claim 1, wherein each period of the gate clock signal corresponds to a respective adjusted display driving period of the plurality of adjusted display driving periods.
 9. The control method of claim 1, further comprising at least one of the following: generating a start signal according to the gate clock signal; generating an output enable signal corresponding to the plurality of adjusted display driving periods, wherein each period of the output enable signal corresponds to a respective adjusted display driving period of the plurality of adjusted display driving periods; and generating a latch data signal corresponding to the plurality of adjusted display driving periods, wherein each period of the latch data corresponds to a respective adjusted display driving period of the plurality of adjusted display driving periods.
 10. A control device for charging time sharing, comprising: a memory unit for receiving and storing image data, the image data including a plurality of pixel data signals corresponding to a plurality of display driving periods, each display driving period associated with pixel data signals of a respective row of a display apparatus; a calculation unit for calculating a plurality of gray variations corresponding to the plurality of display driving periods according to the plurality of pixel data signals; an adjustment unit for adjusting the plurality of display driving periods to generate a plurality of adjusted display driving periods by comparing the plurality of gray variations, wherein the plurality of adjusted display driving period comprises an adjusted first display driving period and an adjusted second display driving period, an adjusted third display driving period and an adjusted fourth display driving period occurring in order and having different durations, and a total duration of the adjusted first display driving period and the adjusted second display driving period is equal to a total duration of the adjusted third display driving period and the adjusted fourth display driving period; and a control signal generation unit for generating a gate clock signal according to the plurality of adjusted display driving periods.
 11. The control device of claim 10, wherein for each gray variation corresponding to a respective display driving period, the calculation unit calculates a maximum change of gray voltage levels between the respective pixel data signals corresponding to the respective display driving period and the respective pixel data signals corresponding to a previous display driving period prior to the respective display driving period.
 12. The control device of claim 10, wherein the plurality of gray variations corresponding to the plurality of display driving periods are calculated by the calculation unit according to the following equation: Vs(Tn)=Max{Δ[Xm(Tn−1)→Xm(Tn)],m=1, . . . ,M},n=1, . . . ,N where Vs(Tn) represents n-th gray variation corresponding to n-th display driving period; Tn represents n-th display driving period; Tn−1 represents a previous display driving period prior to the n-th display driving period; Xm(Tn−1) represents a respective gray voltage level of a respective pixel data signal of m-th column of the display apparatus corresponding to the previous display driving period prior to the n-th display driving period; Xm(Tn) represents a respective gray voltage level of a respective pixel data signal of m-th column of the display apparatus corresponding to the n-th display driving period; Δ(⋅) represents a delta function indicating the difference between respective gray voltage levels; Max(⋅) represents a function indicating taking a maximum of the value in the following parentheses; and n, N, m and M are positive integers, n is between 1 and N, m is between 1 and M.
 13. The control device of claim 10, wherein the calculation unit calculates a first gray variation of the plurality of gray variations corresponding to a first display driving period of the plurality of display driving periods according to pixel data signals corresponding to the first display driving period and pixel data signals corresponding to a previous display driving period prior to the first display driving period and calculates a second gray variation of the plurality of gray variations corresponding to a second display driving period of the plurality of display driving periods according to pixel data signals corresponding to the second display driving period and pixel data signals corresponding to the first display driving period, wherein the second display driving period is after the first display driving period.
 14. The control device of claim 13, wherein the adjustment unit compares the first gray variation with the second gray variation, when the first gray variation is greater than the second gray variation, the adjustment unit increases the first display driving period to generate the adjusted first display driving period and the adjustment unit decreases the second display driving period to generate the adjusted second display driving period.
 15. The control device of claim 14, wherein the first display driving period is shorter than the adjusted first display driving period and the second display driving period is longer than the adjusted second display driving period, and the total duration of the first display driving period and the second display driving period is equal to the total duration of the adjusted first display driving period and the adjusted second display driving period.
 16. The control device of claim 10, wherein the adjustment unit adjusts the plurality of display driving periods to the plurality of adjusted display driving periods according to a ratio of the plurality of gray variations.
 17. The control device of claim 10, wherein each period of the gate clock signal corresponds to a respective adjusted display driving period of the plurality of adjusted display driving periods.
 18. The control device of claim 10, wherein the control signal generation unit generates at least one of a start signal, an output enable signal and a latch data signal, wherein each period of the output enable signal and the latch data signal corresponds to a respective adjusted display driving period of the plurality of adjusted display driving periods.
 19. A control method for charging time sharing in a display apparatus, comprising: receiving image data including a plurality of pixel data signals corresponding to a plurality of display driving periods, each display driving period associated with pixel data signals of a respective row of the display apparatus; calculating a plurality of gray variations corresponding to the plurality of display driving periods according to the plurality of pixel data signals; adjusting the plurality of display driving periods to generate a plurality of adjusted display driving periods by comparing the plurality of gray variations, comprising: comparing a first gray variation corresponding to a first display driving period of the plurality of display driving periods with a second gray variation corresponding to a second display driving period of the plurality of display driving periods, wherein the second display driving period is neighboring to the first display driving period; and when the first gray variation is greater than the second gray variation, increasing the first display driving period to generate an adjusted first display driving period and decreasing the second display driving period to generate an adjusted second display driving period; and generating a gate clock signal according to the plurality of adjusted display driving periods.
 20. A control device for charging time sharing, comprising: a memory unit for receiving and storing image data, the image data including a plurality of pixel data signals corresponding to a plurality of display driving periods, each display driving period associated with pixel data signals of a respective row of a display apparatus; a calculation unit for calculating a plurality of gray variations corresponding to the plurality of display driving periods according to the plurality of pixel data signals; an adjustment unit for adjusting the plurality of display driving periods to generate a plurality of adjusted display driving periods by comparing the plurality of gray variations; and a control signal generation unit for generating a gate clock signal according to the plurality of adjusted display driving periods; wherein the adjustment unit compares a first gray variation corresponding to a first display driving period of the plurality of display driving periods with a second gray variation corresponding to a second display driving period of the plurality of display driving periods, wherein the second display driving period is neighboring to the first display driving period, and when the first gray variation is greater than the second gray variation, the adjustment unit increases the first display driving period to generate an adjusted first display driving period and the adjustment unit decreases the second display driving period to generate an adjusted second display driving period.
 21. A control method for charging time sharing in a display apparatus, comprising: receiving image data including a plurality of pixel data signals corresponding to a plurality of display driving periods, each display driving period associated with pixel data signals of a respective row of the display apparatus; calculating a plurality of gray variations corresponding to the plurality of display driving periods according to the plurality of pixel data signals; adjusting the plurality of display driving periods to generate a plurality of adjusted display driving periods according to the plurality of gray variations; and generating a gate clock signal according to the plurality of adjusted display driving periods to sequentially drive the rows of pixels of the display one row by one row, wherein in each of the adjusted display driving periods, a single row of pixels of the display panel are turned on.
 22. A control device for charging time sharing, comprising: a memory unit for receiving image data including a plurality of pixel data signals corresponding to a plurality of display driving periods, each display driving period associated with pixel data signals of a respective row of the display apparatus; a calculation unit for calculating a plurality of gray variations corresponding to the plurality of display driving periods according to the plurality of pixel data signals; an adjustment unit for adjusting the plurality of display driving periods to generate a plurality of adjusted display driving periods according to the plurality of gray variations; and a control signal generation unit for generating a gate clock signal according to the plurality of adjusted display driving periods to sequentially drive the rows of pixels of the display one row by one row, wherein in each of the adjusted display driving periods, a single row of pixels of the display panel are turned on.
 23. A control method for charging time sharing in a display apparatus, comprising: obtaining pixel data signals of respective row of the display apparatus; and generating a plurality of adjusted display driving periods according to the plurality of pixel data signals; and wherein the plurality of adjusted display driving periods comprises an adjusted first display driving period and an adjusted second display driving period, an adjusted third display driving period and an adjusted fourth display driving period occurring in order and having different durations, and a total duration of the adjusted first display driving period and the adjusted second display driving period is equal to a total duration of the adjusted third display driving period and the adjusted fourth display driving period.
 24. A control device for charging time sharing, comprising: a memory unit for obtaining pixel data signals of respective row of the display apparatus; and an adjustment unit for generating a plurality of adjusted display driving periods according to the plurality of pixel data signals; wherein the plurality of adjusted display driving period comprises an adjusted first display driving period and an adjusted second display driving period, an adjusted third display driving period and an adjusted fourth display driving period occurring in order and having different durations, and a total duration of the adjusted first display driving period and the adjusted second display driving period is equal to a total duration of the adjusted third display driving period and the adjusted fourth display driving period.
 25. A control method for a display apparatus, comprising: generating a plurality of adjusted display driving periods according to gray variance associated with a plurality of pixel data signals, each of the adjusted display driving periods corresponding to a respective row of the display apparatus; and driving the respective row of the display apparatus according to the corresponding one of the adjusted display driving periods; wherein the plurality of adjusted display driving periods comprise a first group of adjusted display driving periods occurring consecutively and a second group of adjusted display driving periods occurring consecutively, the first group of adjusted display driving periods comprises an adjusted first display driving period and an adjusted second display driving period, the second group of adjusted display driving periods comprises an adjusted third display driving period and an adjusted fourth display driving period, wherein the adjusted first display driving period, the adjusted second display driving period, the adjusted third display driving period and the adjusted fourth display driving period occurring in order and having different durations, and a total duration of the adjusted first display driving period and the adjusted second display driving period is equal to a total duration of the adjusted third display driving period and the adjusted fourth display driving period, the second group of adjusted display driving periods having a same total number of adjusted display driving periods as that of the first group of adjusted display driving periods, and a total duration of the first group of adjusted display driving periods is equal to a total duration of the second group of adjusted display driving periods.
 26. The control method of claim 25, further comprising: generating a gate clock signal according to the plurality of adjusted display driving periods.
 27. A control device of a display apparatus, comprising: an adjustment unit for generating a plurality of adjusted display driving periods according to gray variance associated with a plurality of pixel data signals, each of the adjusted display driving periods corresponding to a respective row of the display apparatus; and a control signal generation unit for driving the respective row of the display apparatus according to the corresponding one of the adjusted display driving periods; wherein the plurality of adjusted display driving periods comprise a first group of adjusted display driving periods occurring consecutively and a second group of adjusted display driving periods occurring consecutively, the first group of adjusted display driving periods comprises an adjusted first display driving period and an adjusted second display driving period, the second group of adjusted display driving periods comprises an adjusted third display driving period and an adjusted fourth display driving period, wherein the adjusted first display driving period, the adjusted second display driving period, the adjusted third display driving period and the adjusted fourth display driving period occurring in order and having different durations, and a total duration of the adjusted first display driving period and the adjusted second display driving period is equal to a total duration of the adjusted third display driving period and the adjusted fourth display driving period, the second group of adjusted display driving periods having a same total number of adjusted display driving periods as that of the first group of adjusted display driving periods, and a total duration of the first group of adjusted display driving periods is equal to a total duration of the second group of adjusted display driving periods.
 28. The control device of claim 27, wherein the control signal generation unit generates a gate clock signal to drive the respective row of the display apparatus according to the plurality of adjusted display driving periods.
 29. A control method for charging time sharing in a display apparatus, comprising: generating a plurality of adjusted display driving periods by comparing a plurality of gray variations corresponding to the plurality of display driving periods for driving a respective row of the display apparatus, wherein the adjusted display driving periods depend upon the plurality of gray variations corresponding to the plurality of display driving periods, respectively; and wherein the plurality of gray variations comprise a first gray variation corresponding to a first display driving period of the plurality of display driving periods and a second gray variation corresponding to a second display driving period of the plurality of display driving periods, wherein the second display driving period is neighboring to the first display driving period; and comparing the first gray variation corresponding to the first display driving period with the second gray variation corresponding to the second display driving period, when the first gray variation is greater than the second gray variation, increasing the first display driving period to generate an adjusted first display driving period and decreasing the second display driving period to generate an adjusted second display driving period.
 30. The control method of claim 29, further comprising: generating a gate clock signal according to the plurality of adjusted display driving periods.
 31. A control device for charging time sharing in a display apparatus, comprising: an adjustment unit for generating a plurality of adjusted display driving periods by comparing a plurality of gray variations corresponding to the plurality of display driving periods for driving a respective row of the display apparatus, wherein the adjusted display driving periods depend upon a plurality of gray variations corresponding to the plurality of display driving periods, respectively; and wherein the plurality of gray variations comprise a first gray variation corresponding to a first display driving period of the plurality of display driving periods and a second gray variation corresponding to a second display driving period of the plurality of display driving periods, wherein the second display driving period is neighboring to the first display driving period; and wherein the adjustment unit compares the first gray variation corresponding to the first display driving period with the second gray variation corresponding to the second display driving period, when the first gray variation is greater than the second gray variation, the first display driving period is increased to generate an adjusted first display driving period by the adjustment unit and the second display driving period is decreased to generate an adjusted second display driving period by the adjustment unit.
 32. The control device of claim 31, wherein the control signal generation unit generates a gate clock signal to drive the respective row of the display apparatus according to the plurality of adjusted display driving periods. 